Add a run target to push vignette r scripts through.

r.mk

@@ -4,6 +4,10 @@ RSCRIPT_OPTS = --vanilla
 %.R: %.Rmd
 	${RSCRIPT} ${RSCRIPT_OPTS} -e 'library(knitr);purl("$<", out="$@")'	
 
+%.run: %.R
+	cd $(shell dirname "$<"); ${RSCRIPT} ${RSCRIPT_OPTS} -e 'source("$(shell basename $<)")'	
+
+
 check: 
 	R CMD check --check-subdirs=yes .